Degermination of corn



April 25, 1944. E, c PATTEE 2,347,215

DEGERMINATION oF conn Filed June 14, 1940 wafer corn Shop dryer 3 branaspfraea' ouf rol/0r /2 mill nished mea/ cron sarch l IN VEN TOR.

ELL /S C. PA TTEE Patented Apr. 25, 1944 ,DEGEBMINATION F CQRN EllisCharles Pattee," Cincinnati, Ohio, assignor to National DistillersProducts Corporation, New York, N. Y., a corporation of ylrglniaApplication June 14, 1940, seriellen. 340,418

solaires. lotsa-my. i

This invention relates to the separation of com particles and isconcerned more particularly with the separation of the corn germs fromthe starch and hulls.

The invention will be understood from the following description read inconjunction with the drawing which is a ilow sheet of the processdescribed.,

In the separation of particles of corn kernels, to obtain germs, hullsand starch, it has been the practice to grind the order to separate theparticles satisfactorily. If the material is ground to a coarse meal,itis difllcult to obtain coarse starch particles and coarse germs whichare relatively clean of particles of foreign substance. When the corn isground to a fine state the process of separation is relatively simple.Grinding the corn to a fine meal is satisfactory in the distillationindustry, where it is desirable to place all of the starch into thefermentation mash, which can be easily cooked. But if the meal is to beused for making cereals, such as corn flakes, it is desirable to havelarge grain particles. In addition, in the production of oil from corngerms, it is very diillcult to recover v the oil from ne germ meal whichis the product of the usual separation process.

' 'It is the object of this invention to produce coarse corn meal andcoarse germs at the same time, with resulting economy of operation dueto the higher recovery of oil from the coarse germ. By the process ofthis invention the size of the meal and germ particles may be varied tosuit the needs of the producer. The number and sizes of the mealfractions in corn degermination are determined by the economic outletfor the finished material. For this reason a process by which a numberof diilerent meal sizes may be obtained has an advantage in thatproduction can be regulated in accordance with the demands.

This invention covers a dry corn degerminatlng process ln which themoisture content of the com kernels is maintained below forty percent(40%). In the operation of the process, the whole kernels are steeped asindicated at I in sufficient water to 'raise their moisture content tobetween twenty percent and forty percent (40%). The steeping of the cornmay be conducted at any corn to a fine meal in temperature below thegelatinization point of corn starch. After steeping, the moist corn isdisintegrated in-mill 2, which is preferably an attrition mill havingrevolving disks with the grind ing faces provided with roughenedportions such as ridges or projections. The meal coming from the mili iscomposed of particles of germs, starch and hulls, each of which isrelatively free of the other constituents. Thus, the corn. germs haverelatively little of the starch or hulls adhering to them. This meal iscomposed of particles relatively large in size, and is of such a statethat the corn germ is still whole.

The meal is then dried by any suitable means 3 until its moisturecontent is about ten percent (10%) to ilfteen percent (15%) and it isthen passed over screens 4 which separate it into several fractions suchasyI, 6 and 1 of varying particle sizes. Each of the fractions is sentto a dry classier such as l, 9 and I0 which separates the meal intodiii'erent portions depending upon the relative density. It has beenfound that in the use of a dry classiner, a jigger table operatessuccessfully as a separator of this nature. Since the screened mealsobtained from the steps above-described are composed of particles ofvarying densities, separation may be made on this basis. For example,bran has a high absolute density but due to its large surface inrelation to weight, in a dry classifier it acts as a light material.-Starch is relatively heavy, and this is especially true oi' glutenousstarch. Germs and the soft crown starch from the center of the kernelare relatively light. Thus, when the mixture of germ, bran and starch ispassed over the gravity separator, the heavy glutenous starch isseparated at one end, and the germs and crown starch separate to theopposite end. Between the two ends there is a graded mixtureconcentrated toward the respective germ and giutenous starch ends. Sincethe bran is comparatively light and fluffy it forms as a layer above thegerms, and may be easily separated from the germ by an air draft tocarry it of! of the separator table as indicated at Thethree componentsof the meal may thus be separated into bran, glutenous starch and germs,and are then ready vfor mining. In the milling of the bran, it isreduced in size in a roller mill I2 and any germ or starch particleswhich may have adhered to or been carried along with the bran are thusdisintegrated. In roller mill I3, the glutenous starch is broken up tothe desired meal size. Ii, however, the glutenous starch is desired as acoarse meal, it is not necessary to have any milling action. The millingof the germ fraction as indicated at Il, I5 or I6 results in theflattening of the germs, and at the same time any starch particles whichmay have adhered to the germs are disintegrated and thus easily removed.In the rolling of the germs, it is necessary that they containapproximately ten to iifteen percent (%15%) moisture, since in thatcondition the germs are plastic and the milling only attens but does notbreak them. On the other hand, the starch particles having such amoisture content are iriable and thus disintegrate under the millingpressure.

After the milling operation each fraction may be then screened asindicated at I1, I8 or I9 into the different sizes as desired. In thescreening of the flattened milled germ fractions, the size of theopenings should be approximately'the' same size as the diameters of thegerm meal,"

germs and crown starch and glutenous starch;

particles before they are sent tozlth'e frolle'r 1 In this manner, theilattened germsA-are'sepa-.f rated from the disintegrated starchparticles.

The germs are thus freed of any starch, Abut at the same time havemaintained their oil content, so that in the extraction of their oilthe" operationv is economical as in the case ofthe milling of theoriginal germ itself. The starch may be separated into any desired sizeand as a consequence has many more uses and ,wider markets.

I claim:

1. In the separation of corn kernels into their constituent substances,by a process Which includes steeping such kernels to' a moisture contentbetween twenty percentl (20%) and forty percent (40%), milling suchkernels thereby producing a milled corn broken to the extent necessaryto separate the bran, the glutenous starch and the germs and crownstarch, drying fraction whereby there is separated therefrom a portionconsisting predominantly of germs and crown starch and a portionconsisting predominantly of lglutenous starch.

2. In the separation of corn kernels into their constituent substances,by a process which includes steeping such kernels toa moistureconthesteps of dry gravity :ligging at least one such v fraction wherebythere is separated therefrom a portion consisting predominantly of germsand crown starch and a portion consisting predominantly` of glutenousstarch, and subjecting the material undergoing :ligging to the action ofan` air draft whereby the bran is carried away.

3. In the separation of corn kernels into their constituent substances,by a process which includes steeping such kernels to a moisture contentbetween twenty percent (20%) and forty percent (40%), milling suchkernels thereby producing a milled corn broken to the extent necessaryto separate the bran, the glutenous starch and the germs and crownstarch, drying the milled corn so produced to a moisture content.

substantially between ten percent (10%) and fifteen percent (15%) andthe separation of the milled corn into fractions of different sizes byscreening, each such fraction containing germs and crown starch andglutenous starch; the steps of dry gravity jigging at least one suchfraction whereby there is separated therefrom a portion consistingpredominantly of lgerms, and crown starch and a portion consistingpredominantly of glutenous starch, thereafter rolling the said portionconsisting predominantly of germs and crown starch while maintaining amoisture content between ten percent (10%) and fifteen percent (15%)thereby flattening the germ particles contained in such portion and thenscreening such portion through a screen of a size adapted to retain thesaid attened germ particles while passing the particles of crown starch.

ELLIS CHARLES PATTEE.

